A technical snag on the Delhi Metro’s Blue Line during peak office hours Friday affected services the entire day and left commuters stranded. Metro officials said the fault would be rectified by Saturday morning.

Services on the Dwarka-Noida City Centre/Vaishali Line were badly hit at 9 am. “Train services… are delayed due to a track circuit failure (signalling) near Rajendra Place Metro station since 9.02 am,” said the DMRC in a statement.

It added, “A track circuit dropped (failed) near Rajendra Place station on the line heading towards Dwarka, which forced trains to run at a restricted speed of 25 km/hr between Rajendra Place and Patel Nagar Metro stations. This caused bunching of trains and a slight delay in services.”

Commuters, who were left stranded for an hour until 10 am, vented their ire on social media. “Today, my commute, which normally takes 25 minutes, took an hour and ten minutes. Thankyou delhimetro,” tweeted Colleen Braganza.

“Delhi Metro sets new land speed record on blue line. 40 minutes from Vaishali to Nirman Vihar,” tweeted another commuter, Abhilas Gaur.

According to a DMRC official, the track circuit is a system of signals exchanged between trains and the operating control centre of the metro.

“On Friday morning the circuit failed between Rajendra Place and Patel Nagar metro stations. In such circumstances, the trains which are automatically wired to slow down to a precautionary slow speed to prevent accidents with trains ahead on the line caused a cascading effect and slowed down all trains on the line,” he said.

A DMRC spokesperson said, “We did not have enough time to detect the cause of the snag as the line is one of the busiest. Efforts were made to rectify the problem three times since morning by allowing limited duration access to the technical team at the tracks in the interest of continuity of service. But it appears the track circuit needs detailed investigation to identify the actual cause of problem, for which access to track is required for longer duration. This will be done once services stop for the night.”